This invention relates to piezoelectric transducers and more specifically to such transducers which can provide a high input impedance by coupling a plurality of integral capacitors in series.
Conventional bimorph voice range piezoelectric speakers have an input impedance of less than 100 ohms at a frequency of 1500 Hertz (Hz). A typical 70.7 volt audio distribution system is designed to accept speakers having an impedance of 500 ohms to 10,000 ohms which corresponds to power levels of 10 watts to 0.5 watts, respectively. Thus, a matching circuit or transformer is required to couple a conventional piezoelectric speaker to such an audio system.
It is an object of this invention to provide a piezoelectric transducer having a higher input impedance which can be directly coupled to audio systems requiring such impedances. A further object of this invention is to provide a piezoelectric transducer capable of operating with sustained voltages greater than 20 volts.